/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/

package org.apache.eagle.jpm.mr.history.publisher;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

public class StreamPublisherManager implements Serializable {
    private static final Logger LOG = LoggerFactory.getLogger(StreamPublisherManager.class);

    private static StreamPublisherManager instance = new StreamPublisherManager();

    //Entity Class, StreamPublisher, currently, each Entity Class has only one publisher
    private Map<Class<?>, StreamPublisher> publishers = new HashMap<>();

    public static StreamPublisherManager getInstance() {
        return instance;
    }

    public void addStreamPublisher(StreamPublisher streamPublisher) {
        if (publishers.containsKey(streamPublisher.type())) {
            LOG.warn("stream {} publisher already exists", streamPublisher.type().toString());
        }

        publishers.put(streamPublisher.type(), streamPublisher);
    }

    public StreamPublisher getStreamPublisher(Class<?> type) {
        if (!publishers.containsKey(type)) {
            return null;
        }
        return publishers.get(type);
    }
}
